New methods for statistical analysis of neuropsychological (NP) assessments for mental health services research are being proposed which can provide accurate and precise information about cognitive deficits. The potential benefits of extracting richer and more precise cognitive information from NP data sets are very significant: This analytic approach has the potential to (1) unveil specific relationships between NP deficits and disability; (2) enhance our ability to select treatment and rehabilitative methods that target specific cognitive deficiencies; (3) enhance our sensitivity to detect treatment responses, and to detect differences in cognitive processing between different clinical groups; and (4) save clinical assessment time and assessment costs through sequential testing. The proposed analytic approach includes sequential testing techniques that can drastically shorten the length of NP assessment testing. This project has potentially broad applicability. The techniques and models can be used in other clinical applications when it is of interest to measure cognitive functioning. [unreadable] [unreadable]